Canon FS 3.6 manual Film Base Color, Gamma Correction, Gamma Curve, Grayscale, Halftone, Histogram

Appendices

Dot

The fundamental element of a letter, object or image, which is arranged in vertical and horizontal groups. When scanning a film, the number of dots per inch (dpi) determines the resolution (or density) of a letter, object or image.

Film Base Color

Color negative film that has been developed has an overall orange tint. This is called the film base color. This tint is applied to the film to eliminate unnecessary light and reproduce colors at their best. Each manufacturer uses a slightly different film base color for each of their products. As a result, the scanner must compensate for these differences to reproduce colors faithfully.

Gamma Correction

A setting to make the brightness of image data consistent between the original film (input value) and the computer display (output value) or any further output devices, such as a printer. The relationship between the input and output is called the gamma value. A value of 1 represents output that equals the input. A gamma value of less than one, indicates that the output is brighter than the original and values over one indicate that the output is darker. The graphical representation of the relationship is called the gamma curve (or tone curve). (p. 65)

Gamma Curve

See gamma correction.

Grayscale

An (8-bit) image type utilizing only the brightness data from an image, which is then expressed in black, white and 256 shades of gray.

Halftone

Color tones between the extremes of black and white. In black and white images, halftones are simulated with dithering or diffusion techniques.

Histogram

A graph that shows the distribution of shadows and highlights in an image. An image file contains data with varying brightness values. The brightness values range from shadows to highlights, which are assigned values ranging from 0 to 255.

128